Radio frequency (RF) transceivers have traditionally been located on the ground, with RF signals transmitted to and received from antennas mounted atop radio towers interconnected with the RF transceivers by RF coaxial cables. A move toward remote radio head (RRH) installations, wherein the RF transceivers are themselves located atop radio towers proximate the antennas, has reduced the need for RF coaxial cables to transmit the RF signals between the transceiver and the antenna, but has also increased the demand for electrical power at the top of the radio tower.
Traditional electrical power cables comprise large gauge copper conductors with a circular cross-section. However, such power cables are heavy, difficult to bend and have a high material cost directly related to the rising cost of copper metal.
Cost and weight efficient aluminum power cables are known. However, to deliver the same current capacity as a copper cable, an aluminum power cable requires an increased cross-sectional area. Also, a differential in the thermal expansion coefficient of aluminum material cables and that of the various metals comprising connections/connectors can cause electrical interconnection reliability issues, which tend to increase as the diameter of the clamped portion of the aluminum conductor increases. Moreover, as the diameter of a power cable increases with increasing power capacity, the bend radius of the power cable increases, which makes the cable more difficult to handle and to route.
One proposed solution is offered in U.S. Patent Publication No. 2014/0027153 to Harwath, the disclosure of which is hereby incorporated herein in its entirety. This document discusses a power cable that has a flattened, rather than round, profile, which can reduce weight and bend radius. However, this flattened profile also raises other issues, such as mounting, that need to be addressed.